Assessment of the usability of the EUSAMA and the phase angle method in examining the condition of shock absorbers installed in a vehicle

2021 ◽  
Vol 132 ◽  
pp. 61-79
Author(s):  
Zbigniew Lozia
Keyword(s):  
Phase Angle ◽  
Nonlinear Models ◽  
Assessment Method ◽  
Vertical Movement ◽  
Inertia Force ◽  
Data Sets ◽  
Diagnostic Parameter ◽  
Noticeable Effect ◽  
Shock Absorbers ◽  
Angle Method

The article is a continuation of the author's earlier considerations concerning the methods of testing shock absorbers installed in the vehicle. The work concerns the analysis of the usability of two methods: the EUSAMA method and the phase angle method. The first one examines the minimum ratio of the force in contact between the wheel and the vibration-inducing plate (on which the wheel of the tested suspension rests) and the static value of this force. The second one uses the minimum of the phase shift angle between the excitation (vertical movement of the said plate) and the force in contact between the tire and this plate for diagnosis. Two linear quarter-car models and their description in the frequency domain were used to evaluate two analyzed methods. For both evaluated methods, the monotonicity of the dependence of the diagnostic parameter on the diagnosed one (damping in suspension) is visible; in the case of the phase angle method it is close to linear. The correction of the results related to the inertia of the vibration-inducing plate was considered. The calculations were made for two typical data sets: for the front and rear suspension of a middle-class passenger car. They allow a general qualitative and (to a limited extent) quantitative assessment of the usefulness of the analyzed methods. For the EUSAMA method, the test result has a noticeable effect of the inertia of the vibration-inducing plate. This confirms the legitimacy of correcting the force measured in the diagnostic stand. Values without correction are more optimistic. For cars with a low weight or a lightly loaded road axle (especially the rear axle) of heavier vehicles, low values of the diagnostic parameter are obtained, suggesting a bad condition of the shock absorbers, which is not confirmed by their examination in the state removed from the vehicle. In the second assessed method, there are clear differences between the values of the phase angle obtained based on testing the force in the wheel-plate contact and those obtained for the analysis of the force measured in the test stand. Therefore, the correction for the value of the station plate inertia force is significant. Values without correction are more pessimistic, although it is not justified in the condition of the tested vehicle. The works cited in the article describe several practical drawbacks of the phase angle assessment method. The author points to the importance of further research, much more laborious, with the use of nonlinear models and the necessary experimental verification of the obtained simulation results.

Modeling of an Electromagnetic Vibration Energy Harvester With Motion Magnification

2011 ◽  
Author(s):  
Zhongjie Li ◽  
Zachary Brindak ◽  
Lei Zuo
Keyword(s):  
Large Scale ◽  
Nonlinear Models ◽  
Vibration Energy ◽  
Vibration Energy Harvesting ◽  
Vibration Energy Harvester ◽  
Modeling And Analysis ◽  
Vehicle Suspensions ◽  
Shock Absorbers ◽  
Potential Applications ◽  
Motion Magnification

This paper presents the modeling and analysis of an electromagnetic harvester for potential applications in large-scale vibration energy harvesting such as from vehicle suspensions or civil structures. The kinematics and dynamics of a motion mechanism and generator are considered, including backlash and friction. In this study, a dynamic model for a rack-pinion type regenerative shock absorber has been derived and analyzed based on differential equations. To understand the influence of the friction and backlash on the system, nonlinear models have been created. Simulations are carried out to study the features of the design. The validation of the models is demonstrated by comparing the simulation results with experimental measurements. Guidelines are given for the design of this type of regenerative shock absorbers.

scholarly journals Experience with exchange and archiving of raw data: comparison of data from two diffractometers and four software packages on a series of lysozyme crystals

2012 ◽  
Vol 46 (1) ◽  
pp. 108-119 ◽  
Author(s):  
Simon W. M. Tanley ◽  
Antoine M. M. Schreurs ◽  
John R. Helliwell ◽  
Loes M. J. Kroon-Batenburg
Keyword(s):  
Diffraction Data ◽  
Data Sets ◽  
X Ray Diffraction ◽  
Noticeable Effect ◽  
Raw Data ◽  
X Ray ◽  
Data Comparison ◽  
Data Processing Software ◽  
Software Packages ◽  
Lysozyme Crystals

The International Union of Crystallography has for many years been advocating archiving of raw data to accompany structural papers. Recently, it initiated the formation of the Diffraction Data Deposition Working Group with the aim of developing standards for the representation of these data. A means of studying this issue is to submit exemplar publications with associated raw data and metadata. A recent study on the effects of dimethyl sulfoxide on the binding of cisplatin and carboplatin to histidine in 11 different lysozyme crystals from two diffractometers led to an investigation of the possible effects of the equipment and X-ray diffraction data processing software on the calculated occupancies andBfactors of the bound Pt compounds. 35.3 Gb of data were transferred from Manchester to Utrecht to be processed withEVAL. A systematic comparison shows that the largest differences in the occupancies andBfactors of the bound Pt compounds are due to the software, but the equipment also has a noticeable effect. A detailed description of and discussion on the availability of metadata is given. By making these raw diffraction data sets availableviaa local depository, it is possible for the diffraction community to make their own evaluation as they may wish.

scholarly journals Nutritional assessment in patients with cirrhosis

2012 ◽  
Vol 49 (1) ◽  
pp. 19-27 ◽  
Author(s):  
Sabrina Alves Fernandes ◽  
Lilian Bassani ◽  
Flávia Feijó Nunes ◽  
Maria Eugênia Deutrich Aydos ◽  
Alexandro Vaesken Alves ◽  
...  
Keyword(s):  
Phase Angle ◽  
Nutritional Assessment ◽  
Negative Impact ◽  
Characteristic Curve ◽  
Bioelectrical Impedance ◽  
Impedance Analysis ◽  
Assessment Method ◽  
Receiver Operator Characteristic Curve ◽  
Cross Sectional ◽  
Cirrhotic Patients

CONTEXT: Malnutrition in cirrhotic patients with end-stage disease is common, and the degree of nutritional debilitation can play an important role in the pathogenesis of complications and cause a negative impact on prognosis. However, it involves difficulties and controversies regarding the identification of the best nutritional assessment method. OBJECTIVE: To identify a method that provides a safe and effective nutritional diagnosis. METHODS: Cross-sectional study with 129 cirrhotic patients. Anthropometric measurements, subjective global assessment, hand grip strength and bioelectrical impedance. RESULTS: Through phase angle of bioelectrical impedance analysis (BIA) method, significant associations with Child-Pugh (P = 0.008), age group and gender were observed. The ROC (receiver operator characteristic) curve was generated to determine the best cutoff point of the phase angle of cirrhotic patients, serving as one of the reference parameters for the nutritional assessment with bioimpedance in this study, considering the classification through Child-Pugh score as the reference standard for the clinical conditions of patients with cirrhosis. CONCLUSIONS: The assessment through bioelectrical impedance presented a statistically significant correlation with Child-Pugh score. The identification of phase angle of 5.44º is the new parameter suggested for the classification of the nutritional conditions of cirrhotic patients.

Thermal Inactivation of Campylobacter jejuni in Broth

2012 ◽  
Vol 75 (6) ◽  
pp. 1029-1035 ◽  
Author(s):  
ALI AL SAKKAF ◽  
GEOFF JONES
Keyword(s):  
New Zealand ◽  
The Netherlands ◽  
Campylobacter Jejuni ◽  
Thermal Inactivation ◽  
Nonlinear Models ◽  
Data Sets ◽  
Order Kinetic ◽  
Survival Curves ◽  
First Order ◽  
Log Linear

New Zealand has a high rate of reported campylobacteriosis compared with other developed countries. One possible reason is that local strains have greater heat tolerance and thus are better able to survive undercooking; this hypothesis is supported by the remarkably high D-values reported for Campylobacter jejuni in The Netherlands. The objective of this study was to investigate the thermal inactivation of isolates from New Zealand in broth, using strains that are commonly found in human cases and food samples in New Zealand. Typed Campylobacter strains were heated to a predetermined temperature using a submerged-coil heating apparatus. The first-order kinetic model has been used extensively in the calculation of the thermal inactivation parameters, D and z; however, nonlinear survival curves have been reported, and a number of models have been proposed to describe the patterns observed. Therefore, this study compared the conventional first-order model with eight nonlinear models for survival curves. Kinetic parameters were estimated using both one- and two-step regression techniques. In general, nonlinear models fit the individual inactivation data sets better than the log-linear model. However, the log-linear and the (nonlinear) Weibull models were the only models that could be successfully fitted to all data sets. For seven relevant New Zealand C. jejuni strains, at temperatures from 51.5 to 60°C, D- and z-values were obtained, ranging from 1.5 to 228 s and 4 to 5.2°C, respectively. These values are in broad agreement with published international data and do not indicate that the studied New Zealand C. jejuni strains are more heat resistant than other strains, in contrast with some reports from The Netherlands.

scholarly journals Second Harmonic Phase Angle Method Based on WMS for Background-Free Gas Detection

2021 ◽  
Vol 13 (5) ◽  
pp. 1-6
Author(s):  
Cunguang Zhu ◽  
Pengpeng Wang ◽  
Tongwei Chu ◽  
Feng Peng ◽  
Yongjie Sun
Keyword(s):  
Phase Angle ◽  
Second Harmonic ◽  
Gas Detection ◽  
Free Gas ◽  
Harmonic Phase ◽  
Angle Method

scholarly journals Diagnostics of the On-Vehicle Shock Absorber Testing

2021 ◽  
Vol 23 (3) ◽  
pp. B178-B186
Author(s):  
Piotr Zdanowicz ◽  
Marek Guzek
Keyword(s):  
Shock Absorber ◽  
Standard Procedure ◽  
Diagnostic Methods ◽  
Test Results ◽  
The Road ◽  
Braking System ◽  
Shock Absorbers ◽  
Angle Method ◽  
Half Power ◽  
Vehicle Testing

The practical problems that usually come up during the on-vehicle testing of motor car shock absorbers have been discussed. Results of example tests carried out to the EUSAMA standard procedure were compared to the test results obtained with using newer methods, i.e. the phase angle method and half power bandwidth method (HPBM). The issue of incompatibility of the typical excitation applied by diagnostic suspension testers with one that often occurs in the road conditions has also been raised. It has also been shown that the wear of shock absorbers may affect the value of braking deceleration of cars with ABS (anti-lock braking system) when moving on uneven ground. The main objective of the work was to assess usefulness and reliability of various diagnostic methods intended for the on-vehicle testing of car shock absorbers.

Methods for comparing Salmonella mutagenicity data sets using nonlinear models

1990 ◽  
Vol 240 (3) ◽  
pp. 177-194 ◽  
Author(s):  
W. Gregory Alvord ◽  
Jeffrey H. Driver ◽  
Larry Claxton ◽  
John P. Creason
Keyword(s):  
Nonlinear Models ◽  
Data Sets

scholarly journals Is the World Becoming a Better or a Worse Place? A Data-Driven Analysis

2019 ◽  
Vol 12 (1) ◽  
pp. 88
Author(s):  
Salvatore F. Pileggi
Keyword(s):  
Statistical Data ◽  
Assessment Method ◽  
Data Sets ◽  
Individual Values ◽  
The World ◽  
Study Case ◽  
Value Sets ◽  
Global World ◽  
Global Indicators ◽  
Selection Of

Is the World becoming a better or a worse place to live? In this paper, we propose a tool that can help to answer the question by combining a number of global indicators belonging to multiple categories. The proliferation of statistical data about various aspects of the World performance may suggest that it should be “easy” to evaluate the overall success of human enterprise on this planet. Moreover, it also points out the intrinsic importance in the selection of indicators. However, people have different values, biases, and preferences about the importance of various indicators, making it almost impossible to find an objective answer to this question. To address the variety and the heterogeneity of available indicators and world views, we present the analysis of global World performance as a multi-criteria decision problem, making sure that the assessment method remains as transparent as possible. By dynamically selecting a set of indicators of interest, defining the weights that we attach to various indicators and specifying the desired trends associated with each indicator, we make the assessment adaptive to individual values. We also try to deal with the inherent bias that may exist in the set of indicators that are chosen. As a study case, from various data sets that are openly available online, we have selected several that are most relevant and easy to interpret in the context of the question in the title of the paper. We demonstrate how the choice of personal preferences, or weights, can strongly change the result. Our method also provides analysis of the weights space, showing how results for particular value sets compare to the average and extreme (optimistic and pessimistic) combinations of weights that may be chosen by users.

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